here is a tutorial on how to make one of the mini sigs seen in advent's and Sicloans sig
step 1:
take your rectangular marquee tool and make a wide rectangle and fill it black
http://img209.exs.cx/img209/3844/step19ft.jpg
Step 2:
load selection on the rectangle and make a new layer and using a black and dark grey as colors do a gradient where the grey is at the top and the black is on the bottom
http://img209.exs.cx/img209/7457/step25zr.jpg
Step 3:
make a new layer with the rectangle still selected. now use black and a light grey color as your colors and make a new gradient where the grey is at the top
http://img209.exs.cx/img209/206/step32ct.jpg
Step 4:
on the same layer grab the circular marquee tool and make a selection like so and hit delete.. you now have a 3dish feel
http://img209.exs.cx/img209/6213/step48ee.jpg
step 5:
set this layer to soft light and duplicate it now
now if you want something there just go 2 layers down and put it under the grey gradient
Hope this helps people